Calipees



F. GOULD.

Calipers.

f Patented April 12, v1859.

UNITED STATES PATENT OFFICE.

FAYETTE GOULD, 0F HUNTINGTON, NEW YORK.

CALIPERS.

Specification of Letters Patent No. 23,564, dated April 12, 1859.

Toall whom t may concern:

Be it known that I, Fiixnrrn GOULD, of Huntington, in the county ofSuffolk and State of New York, have invented a new and usefulImprovement in Calipers; and I do hereby declare that the following is afull, clear, and exact description of the same, reference being had tothe annexed drawings, making a part of this specification, in whichmFigure l, is a face or side view of my invention. Fig. 2, is atransverse section of ditto, taken in the line zr, a', Fig. l.

Similar letters of reference indicate corresponding parts in the twofigures.

This invention relates to an improvement in that class of calipers inwhich a sliding jaw is placed on a graduated bar having a stationary jawat one end.

The object of the invention is to obtain by means of these implements amore accli late measurement than usual, and the i11- vention consists inhaving an index attached to the sliding aw and operated by a rack andpinion, and the movement of the jaw, so as to give very minutefractional parts of an inch or other divisions marked on the bar onwhich the movable or sliding jaw works.

To enable those skilled in the art to fully understand and construct myinvention I will proceed to describe it.

A, represents a metal bar which is graduated at one side into inchdivisions. This bar has a stationary jaw B, attached to one end of it,and a jaw C, of similar form is fitted on the bar A, and allowed toslide thereon, said jaw being prevented -from casually moving on the barin consequence of a spring a, which is fitted in the sliding jaw B, andallowed to bear against the inner side of bar A.

The jaws B, C, are simply metal projecw tions extending at right anglesfroi bar A, the inner or face edges of the jaws being parallel with eachother, or, if desiredthey may be curved similar to the llegs of jointedcalipers.

To the sliding jaw B, at its upper part and in front of the graduatedside of bar A, a dial plate D, is attached. This plate is graduated intol128 equal divisions. In the outer edge of the bar A, a sunken rack Z),is fitted, and into this rack a pinion c, gears, said pinion being on ashaft el, which passes through the center of the dial plate D, and hasan index c, on one end which traverses over the dial plate D.

The size of the pinion c, is such that when the sliding jaw B, is movedone inch on the bar A, the index e, will make ust one revolution on thedial plate D, it being understood that the pinion c, is rotated by themovement of the sliding jaw.

From the above description it will be seen that the index c, registersthe fractional parts of inches and on account of the scope obtained forgraduation of said fractional parts ver;7 minute measurements may beobtained, viz., to the 128th part of an inch, and if a large dial plateis employed, more minute divisions may be obtained. The dial plateshould be covered with a stout crystal f, in order to protect the indexe.

Although the several parts are described as being of metal, still awooden bar and jaws maybe used, faced with metal. An entire metalimplement however would be preferable.

I do not claim a stationary and sliding jaw fitted to a graduated bar,for such device has been previously used for. measuring and is wellknown; but, having thus described my invention,

That I claim as new and desire to secure by Letters Patent, is,

In combination with the jaws B, C, and graduated bar A, the dial plateand index c, the latter being actuated by the pinion c, and rack b,substantially as and for the purpose set forth.

FAYETTE GOULD.

lVitnesses FRANCIS M. WHITE, TIMOTHY CARLL.

